Since an endoscope is contaminated once it is used, it must be washed and disinfected or sterilized after use, in order to avoid nosocomial infection. For this purpose, an endoscope washer is used. In accordance with known endoscope-washing procedures, an endoscope is first set in a washing basin of an endoscope washer, then a washing fluid is sprayed through a nozzle provided in the washing basin. In this manner, washing fluid is supplied through the internal lumens which are thereby cleaned by the washing fluid.
After the washing, a disinfectant fluid is sprayed in the same manner as described above or, alternatively the endoscope being cleaned is immersed in a sterilant or disinfectant fluid. In this manner the disinfectant fluid contacts the external surfaces and internal lumens of the endoscope. Thus, the endoscope is disinfected. Thereafter, washing water is sprayed over the external surface and passed through the internal lumens of the endoscope, thereby rinsing the endoscope. Finally, air is supplied through the tube of the endoscope, and the washing basin is heated, to dry both the outer surface and the inside of the endoscope tube being cleaned.
Conventional endoscope washers which are used to perform the above described cleaning procedure have the following problems. In the known endoscope washers, the tubes and fluid holding tanks tend to become colonized with bacteria, which contaminates the washer. Because of this, most washers have a special self-disinfection process which the user must periodically perform to disinfect the washer itself. However, this self-disinfection process may not de-contaminate all internal portions of the washer, and may require manual steps on the part of the user. Accordingly, the conventional self-disinfection process is an inconvenience to perform.
In general, the known endoscope washers use large amounts of water for washing. If this water is unprocessed, the tap water brings organisms into the washer, which increases the need for self-disinfection. While sterilization of the water used for washing by, e.g., filtering or UV treatment, offers one way of reducing the need for self-disinfection, the expense of high processing large quantities of tap water to sterilize the water must be incurred.